Illinois First Employee Checklist in 2026: State Registrations an LLC Must Finish Before Payroll

An Illinois first employee triggers a state checklist that has to be cleared before the first paycheck.

The LLC was formed. The bank account is open. The owner is ready to make the first hire. Then the inbox fills up with filings: a Form REG-1 for state income tax withholding, a Form REG-UI-1 for unemployment insurance, a New Hire Reporting setup, a workers’ comp policy, and the federal W-4 and I-9 paperwork that runs alongside everything else. None of it is forgiving if it sits in the inbox.

This article walks through the order these registrations need to happen in, the state agencies involved, the deadlines that are easy to miss, and the mistakes that show up most often when an Illinois LLC hires its first employee in 2026.

Watch the short video below for a quick walkthrough of the Illinois first-employee checklist.

The order the registrations need to happen in

The registrations do not all happen at the same agency, and the sequence matters. The practical order in 2026:

The Federal Employer Identification Number (FEIN) is the trigger for everything downstream. Without an FEIN, IDOR will not accept a withholding registration, IDES will not assign an unemployment account number, and the federal new-hire reporting hub at the Office of Child Support Enforcement will not accept filings. The FEIN is free from the IRS and takes about 15 minutes.

The Illinois Business Registration (Form REG-1) with the Illinois Department of Revenue (IDOR) handles state income tax withholding. The same online session through the MyTax Illinois portal also opens the unemployment insurance account with the Illinois Department of Employment Security (IDES). One registration, two account numbers.

New Hire Reporting setup with the Illinois New Hire Directory has to be in place within 20 days of the first employee’s first day on payroll. The directory is operated by IDES under the federal Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWOR).

Workers’ compensation coverage has to be in force on the day the first employee starts work. Illinois is one of a small number of states with no employer-size exemption. Coverage is purchased from a private carrier (or secured through the Illinois Workers’ Compensation Commission self-insurance program).

Federal W-4, I-9, and W-2 paperwork runs in parallel with the state registrations. The LLC should not let federal forms outrun the state registrations, but federal forms should not wait for state registrations either.

The order matters because some registrations build on others. IDOR will not assign a withholding account number without an FEIN. IDES will not assign a UI account number without a registration filing. Workers’ compensation carriers want the FEIN and the principal address. Federal W-4 and I-9 forms have to be in the LLC’s files before the first paycheck is issued, but the state registrations do not depend on them.

IDOR withholding registration (Form REG-1)

The Illinois Department of Revenue (IDOR) administers state income tax withholding for wages paid in Illinois. Every LLC that pays wages to an Illinois employee is required to withhold Illinois income tax from those wages and remit it to IDOR.

The registration is Form REG-1, the Illinois Business Registration Application. The LLC can file REG-1 electronically through the MyTax Illinois portal, by mail, or in person at an IDOR regional office. The online MyTax Illinois registration is the fastest path and typically processes in one to two business days.

When the LLC registers with IDOR for withholding, IDOR assigns a Taxpayer ID that becomes the LLC’s account number for filing Form IL-941 (the Illinois Withholding Income Tax Return) and for remitting withholding payments using Form IL-501 (the Withholding Payment Coupon).

The IDOR overview of withholding requirements is at tax.illinois.gov. The MyTax Illinois portal at mytax.illinois.gov is where the LLC files REG-1, files IL-941, and remits payments electronically.

IDOR contact: (217) 785-3707.

IDES unemployment insurance (Form REG-UI-1)

The Illinois Department of Employment Security (IDES) administers state unemployment insurance (UI). UI is funded entirely by the employer. The employee does not contribute. Contributions are calculated as a percentage of the LLC’s payroll based on the LLC’s experience rating under the Illinois Unemployment Insurance Act.

The registration is the REG-UI-1 form (formerly UI-1), the Report to Determine Liability Under the Unemployment Insurance Act. The 30-day clock starts on the date the LLC first employs workers in Illinois, not the date the LLC is formed. Under Illinois Public Act 97-0689 and the IDES Employer Resources page at ides.illinois.gov, the combined registration through MyTax Illinois is the cleanest path because the LLC provides the same identifying information once and ends up with both the IDOR Taxpayer ID and the IDES UI account number.

The REG-UI-1 form is available as a PDF from IDES at ides.illinois.gov.

Once registered, IDES assigns the LLC a UI account number. The LLC uses that account number to file quarterly contribution and wage reports (Form UI-3/40) and to remit UI contributions.

Quarterly UI-3/40 deadlines: April 30, July 31, October 31, January 31.

IDES contact: 1-800-247-4984.

New Hire Reporting to the Illinois New Hire Directory

The Illinois New Hire Reporting requirement comes from federal law — the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 — which requires every employer to report new hires to a state directory within 20 days of the employee’s first day on payroll. In Illinois, the directory is operated by IDES.

The information the LLC has to provide for each new hire includes the employee’s name, home address, and Social Security number; the date of hire (the employee’s first day of work for pay); the employer name, address, and Federal Employer Identification Number; and an address where income withholding orders should be sent (optional, but the LLC can use this to direct child support withholding orders to a specific office).

The LLC can register as a new-hire reporter online, by fax, or by mail through the IDES New Hire Directory page at ides.illinois.gov. The 20-day clock is short — the LLC that hires on the 1st of the month and waits to set up new-hire reporting on the 25th is already late.

The Illinois New Hire Directory is at 115 S. LaSalle St, Chicago, IL 60603-3820. The 24-hour fax line is 1-217-557-1947.

The federal and state child support enforcement agencies use the New Hire Directory to locate absent parents and to initiate income withholding orders. The LLC that does not report is the LLC that finds out about the missed filing when a child support withholding order arrives with no matching hire record.

Workers’ compensation coverage

Illinois is one of a small number of states that requires nearly every employer to carry workers’ compensation coverage from day one. The Illinois Workers’ Compensation Act at the Illinois Workers’ Compensation Commission applies to every employer with even one employee, including LLCs with a single W-2 employee.

The LLC’s workers’ compensation obligation is independent of the IDOR withholding registration and the IDES UI registration. The LLC cannot substitute one for the other. Workers’ comp is purchased from a private insurance carrier (or, in some cases, secured through the Illinois Workers’ Compensation Commission self-insurance program). The carrier provides a policy number that the LLC’s payroll records should reference, and the carrier files proof of coverage with the Illinois Workers’ Compensation Commission.

The LLC that fails to carry workers’ comp faces a stop-work order from the IWCC, fines of up to $500 per day of noncompliance, and personal liability for any workplace injury that occurs during the gap.

Sole proprietors and members of an LLC are not automatically exempt. The LLC has to file the appropriate election under 820 ILCS 305 to opt out of coverage for the owner, and only the owner is eligible — once a W-2 employee is added, coverage is mandatory.

Federal paperwork that runs in parallel

The state side of the checklist is the topic of this article. The federal side has to be in place at the same time, and the LLC should treat the two streams as parallel tracks.

The federal checklist for the first employee in 2026:

Form W-4 (Employee’s Withholding Certificate) is completed by the employee on or before the first day of work, kept on file by the LLC, and used to determine federal income tax withholding. The 2026 W-4 is the current revision.

Form I-9 (Employment Eligibility Verification) is completed within three business days of the first day of work. The employee fills out Section 1; the LLC fills out Section 2 and verifies the identity and work-authorization documents.

Form W-2 (Wage and Tax Statement) is issued to the employee by January 31 of the following year. The LLC also files a W-2 copy with the Social Security Administration.

Form W-3 (Transmittal of Wage and Tax Statements) is filed with the SSA along with the W-2 copy.

Form 941 (Employer’s Quarterly Federal Tax Return) is filed quarterly with the IRS to report federal income tax withholding, Social Security, and Medicare taxes. Some LLCs with small payrolls may qualify to file Form 944 annually instead.

Form 940 (Employer’s Annual Federal Unemployment Tax Return) is filed annually with the IRS to report FUTA tax.

The LLC’s payroll provider typically handles the federal filings if the LLC uses a payroll service. If the LLC runs payroll itself, the LLC owns all six forms.

The practical deadline stack for an Illinois LLC in 2026

The deadlines fall in a fixed order. The LLC should treat them as a single deadline stack rather than independent items.

Day zero (first day of work): workers’ compensation coverage must be in force. Form W-4 must be in the file. Form I-9 Section 1 must be completed by the employee.

Day three: Form I-9 Section 2 must be completed by the LLC, including document verification.

Day 20: New Hire Reporting must be filed with the Illinois New Hire Directory.

Day 30: IDES registration (Form REG-UI-1) must be filed under Illinois Public Act 97-0689. IDOR withholding registration is not bound to a specific deadline, but the LLC must register before paying wages — so practically it has to be done before the first paycheck.

Quarterly thereafter: Form UI-3/40 with IDES (due April 30, July 31, October 31, January 31); Form IL-941 with IDOR (same calendar).

Annually: Form W-2 and W-3 to SSA by January 31; Form 940 to IRS by January 31; Form IL-941-W-3 to IDOR (annual reconciliation) by January 31.

Where Illinois LLC owners most often get this wrong

The mistakes that come up most in 2026:

Starting payroll before IDOR and IDES registrations are in place. The first paycheck either waits until the registrations clear or the LLC pays wages without a Taxpayer ID and a UI account number, then scrambles to back-fill the filings. Neither is good.

Missing the 30-day IDES deadline. The Public Act 97-0689 timeline is short, and a newly-formed LLC often does not have the UI registration on the owner’s first-week checklist. Penalties under the Illinois Unemployment Insurance Act include interest on unpaid contributions and personal liability for responsible persons.

Skipping New Hire Reporting. Federal and state child support enforcement use the New Hire Directory to locate absent parents and to initiate income withholding orders. The LLC that does not report is the LLC that finds out about the missed filing when the withholding order arrives.

Treating workers’ comp as optional for the first employee. The Illinois Workers’ Compensation Act at iwcc.illinois.gov applies from the first W-2 employee forward. Sole proprietors and members of an LLC are not automatically exempt.

Confusing the IDOR Taxpayer ID with the federal FEIN. The two are different identifiers from different agencies. The UI account number from IDES is a third identifier. Each agency wants its own number on its own form.

Missing the distinction between quarterly UI-3/40 reporting and monthly wage reporting. A small LLC with one or two employees files quarterly. A larger LLC may also file monthly wage reports for the first two months of each quarter. The MyTax Illinois portal handles both, but the LLC has to know which schedule applies.

The practical rule for 2026

The practical rule for an Illinois LLC in 2026 is that the first employee triggers a fixed checklist that has to be cleared before the first paycheck, and the checklist has a 30-day outer deadline.

The most efficient path is the combined registration. FEIN first, then a single MyTax Illinois session at mytax.illinois.gov that registers with both IDOR for withholding and IDES for unemployment insurance. Add the New Hire Reporting setup to the same week through the IDES New Hire Directory. Put workers’ compensation coverage in place before the first day of work through a private carrier. Treat federal W-4, I-9, and W-2 as parallel work, not as something to do after the state registrations clear.

For an LLC that wants the state registrations, the workers’ compensation policy, and the federal paperwork handled as a single coordinated onboarding — typically when the LLC is bringing on its first W-2 employee or expanding from owner-only to a small team — set up an Illinois first-employee onboarding through Rapid Registered Agent. The Illinois first employee checklist is a fixed sequence with hard deadlines, and the steps are easier to run as a coordinated onboarding than as five independent tasks.

Watch the second video below for a step-by-step walkthrough of how to file the combined registration through MyTax Illinois.

Related reading

• Illinois Annual Report and Registered Agent Changes for LLCs in 2026 — establishes that the LLC is a registered Illinois entity before the first-employee checklist runs
• Illinois Articles of Amendment for LLCs: Common 2026 Update Scenarios — useful if the first hire triggers an amendment (such as adding a manager-managed election change)
• Illinois LLC Documents: Example and State Comparisons — covers the LLC’s full state-level document set alongside the first-employee checklist

If an Illinois LLC is hiring its first employee, the state has a fixed checklist with a 30-day outer deadline. The MyTax Illinois portal handles both IDOR withholding and IDES unemployment insurance in a single registration, New Hire Reporting has to be in place within 20 days of the first day on payroll, and workers’ compensation coverage has to be in force from day one under the Illinois Workers’ Compensation Act.

Set up an Illinois first-employee onboarding through Rapid Registered Agent.